Amyloidal structures have been found in the body. Some have been found as plaques and are implicated in the progression of certain diseases. For example the relationship of plaques of amyloidal fibrils to Alzheimer's disease has been extensively studied. Moreover the presence of such plaques has been studied in relation to other diseases such as amyloidisis, diabetes mellitus Type II, Parkinson's disease, Huntington's disease and spongiform encephalopathies such as CJD. Adopting recent recognised nomenclature1, amyloid is used herein to refer to certain intracellular and extracellular protein aggregations in vivo. In particular within the present invention the term amyloid includes protein with cross beta sheet quaternary structure which is usually in fibrillar form. For amyloid aggregations synthesised from proteins or peptides in vitro we use the term amyloid-like. The structure in question is described in more detail below and with reference to the drawings.
Generally speaking the amyloid or amyloid-like structure can be recognised by many techniques and in particular is known for its strong affinity for the dye Congo red and a typical green-gold birefringence after such staining under cross-polarized light (for samples of optimum thickness). Additionally amyloid or amyloid-like structure can be identified by staining with thioflavin T or thioflavin S. Fibrils can be characterized at the molecular level by x-ray diffraction. In particular, the beta sheet configuration of the amyloid or amyloid-like structure can be recognised by characteristic bands (such as in X-ray diffraction) which correlate to inter-strand distances in the beta sheet.
The ability of algae to adhere to a wide range of natural and artificial surfaces in marine, freshwater and terrestrial habitats is thought to be due to the secretion of extracellular polymeric substances (EPS) that have a diversity of structure, chemical composition and function2. The mechanism of adhesion typically involve initial, reversible attachment to a surface followed by an EPS secretion that forms a more permanent adhesive2. Similar (permanent or temporary) adhesive mechanisms, which involve the deposition of EPS, are found extensively in nature, not only in plants, but also invertebrate organisms such as barnacles and mussels and indeed in other organisms such as parasites and bacteria.
WO 02/042321 (Dobson et al) discloses a method of incorporating peptide into amyloid fibrils. In particular, the document describes a method of creating amyloid fibrils from human plasma protein which have two or more distinct molecular species. The distinct species are said to associate within the beta-sheet array. The document posits creating fibrils which in turn can be used to generate a plastic or scaffold without any supporting examples. The plastics materials are suggested for use as a support to grow cells for grafts or transplant. Controlled disassociation of fibrils is mentioned as being useful for controlled release of drugs. Further mention is made without example of use of gels to encapsulate drugs (capsules are mentioned) or of impregnating a gel with drugs. Fibrils which are tubular with a hollow core or with flat ribbon or twisted morphologies are mentioned as possibilities though again no examples are given. All of the teaching of WO 02/04321 relates to creating materials for use in vivo and formation of the fibrils in vivo with the intention of treating diseases in animals such as those described above.
WO 00/17328 also to Dobson et al, describes amyloid fibrils free of other protein and processes for their preparation. The teaching of WO 00/17328 relates to creating materials for use in vivo and formation of the fibrils in vivo with the intention of treating diseases such as those described above. For example bovine and human amino acid sources are employed. The primary objective of WO 00/17328 is providing treatments for such diseases although mention is made, without example, of having metallised fibrils forming wires for electronics, or fibrils being made into plastics or made into structures.
U.S. Pat. No. 6,376,636 (Hansma et al) describes a modular, energy dissipating material and method for using it. The invention investigates the fracture resistance of the abalone shell. The study included consideration of the energy dissipating properties of Lustrin A. The sawtooth-like pattern was shown to reflect the success of unfolding of folded domains within a single molecule of Lustrin A.
WO 2005/033131 (Larsen et al) discloses production of amyloid fibrils from wheat flour proteins. Wheat proteins and in particular a glutenin material were chosen by Larsen et al because they are rich in glutamine residues (wheat proteins are considered to be relatively large compared to the average protein—possibly 800 residues or more and of those approximately a third are glutamine residues). Glutamine rich material have been thought to be necessary for the formation of amyloid-like structures. Amyloid-like fibrils by Larsen et al were formed from wheat flour over a period of 1 to 3 months.